.H 1 "FIREFOX FAILURE RATE GOALS"

.H 2 "Basic CPU"

The failure rate goal for FIREFOX is 8%/year for a one Mbyte system.
This goal will be a challenge to meet and will have an effect on many design
decisions.  The table below shows the failure rate budgets for
each part of the SPU.

.DF
.TB "Failure Rate Budget"
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Item\ Budget\ Estimate
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CPU and ROM\.9%\.9%
IO, Keyboard Clock, etc.\1.8%\1.9%
1 Mbyte RAM\1.3%\1.3%
Power Supply\2%\ ?
Mechanical and interconnect\2%\ ?
_
Total\8%
.TE
.DE

The CPU, Keyboard, IO, and RAM failure rates were modeled and the budgets
were set to be very close to the results.  This causes some concern because
it does not leave any margin for things that were overlooked.  The models and
budget assumes that a large gate array is used to interface
the internal IO, KB, RTC, and EAROM to the DIO bus.

The warranty failure rate data show that the failure rate for connectors is
very low.  It has always been assumed that connectors have a high failure
rate.  This discrepancy needs to be investigated further.
The failure rate estimates assume that the failure rate for the
connectors is low.

The failure rate goal for the RAM board assumes that a single hard failure
per bank of RAM does not cause a system failure and does not need to be repaired.

The power supply and mechanical and interconnect budgets are significantly
lower than what they were on CHEETAH.  It has been assumed that DC fans will
be used in FIREFOX.  Warranty data show that the two DC fans that we plan to
use could each have a failure rate of more than 1%.  The data indicate that
AC fans are 8 to 10 times better.  The reason for the difference needs to
be investigated.

.H 2 "Display Logic"

The failure rate goals for the display logic were set by multiping the
factory cost by 4 to get the selling price and using 1% per K$.  The table
below shows the goals for each of the proposed display systems.
 
.DF
.TB "Display Logic Failure Rate Goals"
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System\ Budget\ Estimate
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4 Planes\3.5%\3.5%
8 Planes\6.5%\6.5%
24 Planes\17%\17%
.TE
.DE

The failure rate estimates show that the failure rate goals can be met.
Like the rest of the SPU there is very little margin to allow for
unexpected problems.

.H 2 "Monitor Failure Rate"

For the most part the monitors will be OEMed (Some changes may be made.).
The plan at this time is to use the GATOR monitors for FIREFOX.  The
table below shows the failure rate goals for each of the monitors.

.DF
.TB "Monitor Failure Rate Goals"
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Monitor\ Budget\ Estimate
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17 Inch B & W \2.5%\10%
19 Inch Color\6%\18%
.TE
.DE

The goals were set by assuming 1%/K$ selling price.  Nothing has been done
to insure that these goals will or can be met.  The estimates are the
current failure rate goals are for the monitors.

.H 2 "Failure Rate Goals for Options"

The options being developed in the FIREFOX group are the floating point
option and the 4 Mbyte RAM board.  It appears that these options should have
no problem meeting there failure rate goals.  The table below shows the goals
and the estimated failure rates.

.DF
.TB "Failure Rate Goals and Estimates for Options"
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Option\ Budget\ Estimate
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Floating Point Chip Set\1.5%\.75%
4 Mbyte RAM board\8%\2%
.TE
.DE

